Syria has agreed to keep its forces six miles (10km) from the Turkish border in the wake of this week's deadly shelling incident, Turkish media have reported.

Such a move would amount to a buffer zone, fulfilling a longstanding request by Syrian opposition groups that would allow rebels to operate freely and civilians to seek refuge.

Syria has not confirmed the claim and Ankara has made no official announcement. However, several Turkish media outlets, citing well-placed sources, claimed that a deal had been struck.

Opposition groups have implored Turkey and the international community to establish an area in which they can move without fear of jets and helicopters, claiming it would be a significant step in their 19-month battle to oust the regime of Bashar al-Assad.

However, the demands have been rejected by Ankara, as well as the US and Nato, who have all repeatedly balked at suggestions that they intervene directly in the conflict. A buffer zone would not be effective unless it was enforced militarily, something that Turkey has so far been unwilling to do. However, the Syrian shelling of the Turkish border town of Akcacle has spurred Ankara to recalibrate its military options to deal with the growing crisis across the southern border.

On Thursday, the Turkish parliament approved a bill that would allow its military to launch cross-border raids at any point in the next year. Prime minister Recep Tayyip Erdogan said on Friday that Turkey was not pushing for an escalation with its once close ally. "We are not interested in war," he said. "But we're not far from it either."

Syria said it was waiting for the results of an investigation before publicly assigning blame for the shelling, which killed five Turkish civilians and wounded nine more. But it has privately conceded it was at fault and did not respond to a barrage of retaliatory Turkish shellfire, which is thought to have killed several Syrian soldiers.

The shelling came hours after Erdogan called on Syria not to test Turkey's patience. The Anadolu Agency quoted Governor Celalettin Lekesiz as saying a mortar shell hit 50m inside the border in a rural area near the village of Asagipulluyaz in Hatay province. No one was hurt by the mortar, but Turkish troops based in the area immediately responded with fire, he said.

Video footage uploaded to the internet on Thursday appeared to show a military helicopter being struck then crashing to the ground over Damascus, not far from where rebels claimed earlier on Friday to have seized control of a missile base.